Telephone substation apparatus



2 Sheets-Sheet 1 L. A. REED TELEPHONE SUBSTATION APPARATUS Filed June27, 1944 oct. 15, 194e.

0t- 15, 1946 L. A. REED 2,409,588

TELEPHONE SUBSTTION APPARATUS Filed June 27, 1944 2 Sheets-Sheet 2INVENTOR. EL/7WD A. REED BY AMW HTToR/Vsv' Patented Oct. 15, 1946TELEPHONE SUBSTATION APPARATUS Leland A. Reed, Rochester, N. Y.,assignor to The Stromberg-Carlson Company, Rochester, N. Y., `acorporation of New York Application June 27, 1944, Serial No. 542,344

4 Claims.

This invention relates to a novel construction oi the component partsprovided in a subscribers substation apparatus and especially within thebell box forming a part thereof, either where this bell box is used as aseparate part of the apparatus or where it is incorporated as a part ofthe complete telephone assembly.

Thebell box of the mentioned apparatus includes, besides a ringer, suchelectrical components as an induction coil and one or more capacitorunits. Prior to this invention, it has commonly been the practicetoemploy several terminal strips on one or both sides of which there areprovided screw type terminals plus solder type terminals, bothelectrically Aconnected to the respective leads from the severalcomponents. Con ductors having their ends fastened by the screws of theterminals complete the circuit network.

As a result of the mentioned arrangement wherein the terminal strips, aswell as the induction coil and the capacitors with the interconnectingconductors, are exposed to the atmosphere, current leakage and corrosiontake place.

In accordance with the main feature oi the invention there is provided anovel substation construction wherein the induction coil, as well as thecapacitor units with their interconnecting conductors, are sealedagainst the atmosphere and are therefore substantially free fromcorrosion or other electrical failure due to the,

presence of moisture.

Another feature of the invention relates to the reduction withinsubstation apparatus, of the number of terminals exposed to theatmosphere and to the reduction of long leakage paths between theremaining terminals that are so exposed.

Other features will appear from the detailed description and claims whentaken with the drawings in which Fig. 1 is a diagrammatic showing of thesubstation apparatus construction of the present invention,l the portionthereof enclosed by the dotted rectangle representing the equipment tobe mounted within the bell box or desk stand base;

Fig. 2 is a schematic showing of the circuits and apparatus of Fig. 1;

Fig. 3 is a top View of a sealed assembly unit for mounting within thebell box or base of a cradle type desk stand, indicated in dotted lines;

Fig. 4 is a vertical section through the unit of 2 tional antiside tonetelephone substation circuit incorporating the present invention,although the invention is not to be limited to this disclosure since itis applicable to various types of substation circuits either with orwithout a dial sender. rThe telephone circuit as shown most simply inFig. 2, includes within the bell bo-X or in the base of the cradle deskstand (indicated in dotted lines lin Fig. 4), a ringer 5, ringercapacitor units El I of the telephone line extends through the impulsesprings I3 of the dial, thence through one winding I4 of the inductioncoil, conductor I5 through the transmitter I9, conductor I6 and Xcontacts of the hook-switch, to the other side L2 of the telephone line.There is bridged across the terminals of the transmitter IIJ, a circuitincluding the receiver II, conductor Il, Y contacts of the hook-switch,capacitor 9, and the induction coil winding I9, and in parallel with thereceiver i6, there is connected the winding 2i) of the induction coil,all in accordance with a conventional type of antiside tone circuit. Theringer 5 isbridged across the line conductors LI and L2 in series withthe capacitor elements 6 and 'i which are connected in parallel. Itshould be mentioned that the parallel arrangement of the capacitors isprovided since the capacitance of the two elements is necessary to onetype of ringer While a single one of these elements suices for anothertype of ringer.`

In a substation circuit, diagrammatically illustrated in Fig. l,v thecapacitor 9 and capacitor elements 6 and 1, as well as the windings ofthe induction coil 8 are enclosed in a receptacle 25, illustrated inFigs. 3, 4 and 5, wherein these elements are embedded and sealed in amoistureproof compound. It will be noted from Fig. 1 that the conductorsconnecting these electrical elements are contained within the receptaclein order to be embedded in the compound. This arrangement permitssoldered connections between the conductors and the outlet leads ofthese mentioned elements. '1"ne sealing of these conductors and thesoldered connections prevents corrosion and also tends to obviateelectrical leakage between the conductors. The receptacle comprises agenerally rectangular, rather shallow container open at the front, asviewed in Fig. 5. Two opposing sides of the receptacle are provided withpairs of perforated lugs 2S by which the container can be mounted in abell box or within the base of the cradle telephone. The inner portionof -the receptacle -is provided. with ribs 2 which, with the side wallsof the receptacle, define three areas to receive the induction coil 8and the two capacitor elements 6 and as well as capacitor unit 9. Theseribs tend to hold the electrical units in spaced relation during thetime that the compound is being poured into the Yreceptacle to immerseand seal these units and the conductors connected therebetween. Certainof these conductors are indicated only in Fig. 4. The right-hand end ofthe receptacle, as illustrated, is off-set to provide a shoulder .28.This shoulder is provided with a series of connection terminals, such as4Q, which are molded in the receptacle at the time when it is made. Itwill be noted from Fig. 4 that the lower end of each connection terminalis embedded in the sealing compound. Thus, there is no danger ofelectrical leakage or corrosion where the conductor, connected to thelower end of this terminal within the receptacle, is embedded .in thesealing compound. However, the upper end of the terminal is exposed atthe shoulder 26 to provide a screw type connection to an externalcircuit. The upper surface of the shoulder 28 is provided with a seriesof upstanding ribs 30 which tend .to increase the length of possibleleakage paths between adjacent terminals. The left end of thereceptacle,

as viewed in Fig. 4, is stepped to provide a pair of shoulders 33 and 34similar to the shoulder 28. The shoulders 33 and 34 are likewiseprovided with a series of connection terminals similar to those alreadydescribed. Ribs 36 and 31 are Aprovided on the upper surfaces of theshoulders to separate` adjacent connector terminals.

While the circuit network of the substation is shown schematically inFig. 2, the arrangement of the electrical components in the receptacleand the actual wiring of the substation circuit is illustrated inFig. 1. The arrangement will be understood by tracing the connectionsthrough the receptacle. The side LI of the telephone line is fastened tothe screw terminal 46 exposed on the shoulder 28 of the receptacle. Fromthis terminal the connection 4I extends through the sealing compound tothe screw terminal 42 with its screw head exposed on the lower shoulder34 at the left end of the receptacle. From this terminal, the connectionextends through the exposed conductor 43, impulse springs I3 of thedial, exposed conductor 44, to the screw terminal 46. From thisterminal, the connection .extends through the embedded conductor 41,winding I4 of the induction coil, embedded conductor 48, to the terminal4S on the upper shoulder 33 of the receptacle. `Thence the connection.extends through'the exposed conductor 5I to transmitter I 0. From thetransmitter, Ithe connection extends through `the exposed conductor 52,screw terminal 4 which is internally connected to the screw terminal 55.4This terminal is connected by the external conductor 56, through the Xcontacts ofthe hook-switch and conductor 51 to the terminal 53. Terminal59 is connected by the sealed conductor 60 to the terminal 6I located atthe shoulder t8, terminal 6I being connected to the other side L2 of theline.

The receiver circuit includes the previously mentionedexterna-lconductcr 52 and the receiver I I, external conductor 62 toterminal 64 which is internally connected to terminal 65, externalconductor Y hook-switch contacts, conductor 61', terminal 68. From thisterminal, there extends a sealed conductor 66, through the capacitor 9,sealed conductor 1I, winding I9 of the induction coil, sealed conductorI3 to the terminal 49. The third winding 26 of the induction coil, hasone of its leads connected by the sealed conductor I6 to terminal 54 andits other lead is connected by the sealed conductor 'l'I to the terminal68. The external conductor 'i3 from the terminal 55 and the externalconductor 'i9 from the terminal 65 extend to the dial shunt springs 60.Incidentally, when ythe dial sender is not provided, conductors i8 and'59 are omitted. Also the conductors 43 and 44 are omitted and terminals42 and 46 are strapped together.

The ringer is connected into the network by the sealed conductor 82which extends from the terminal 6I to terminal 83. The terminal 83. isconnected by the external conductor 84 to one side ofthe ringer 5, whilethe other side of the ringer is connected by conductor 85 to terminal86. With certain types of ringers, both capacitor elements 6 and 'I areelTective by being connected in multiple by the sealed conductors 88 and89 to terminals S6 and 87 which are externally strapped together byconductor 95. However, when one of the capacitor elements is suflicient,this strap is omitted. The common terminals of these capacitor elementsare connected by the sealed conductor 92 to the terminal 45. Terminal 94which can be connected to ground is connected by the sealed conductor 95to the terminal 86. Terminal S6 is used when a ground ringing circuit isemployed instead of the ringing circuit shown.

What I claim is:

1. Telephone substation apparatus comprising a transmitter, a receiver,a hook-switch and a ringer, electrical components connectible with saidtransmitter and receiver, a receptacle having an offset portion dening ashoulder with a surface generally parallel to the bottom of thereceptacle at each end thereof, a plurality of terminals mounted in eachshoulder to extend in a direction generally perpendicular to the surfaceof said shoulder, each terminal having an external end accessible fromthe outside of the receptacle at the mentioned surface of its relatedshoulder and having its inner end terminating within the receptacle,said electrical components including an induction coil with its severalwindings and a capacitor contained within the receptacle, conductorswithin said receptacle electrically connecting said units with oneanother and with the inner ends of said terminals, a fusible compound inthe receptacle sealing said conductors and said components therein,certain of said external terminals being connectible to the two sides ofa telephone line, certain others of said external terminals beingelectrically connected to seid transmitter, said receiver and saidringer.

2. Telephone substation apparatus comprising a transmitter, a receiver,a hook-switch and a ringer, electrical components connectible with saidtransmitter, receiver and hook-switch, a receptacle having a steppedside wall defining a shoulder with a surface generally parallel to thebottom of the receptacle at each end thereof, each shoulder beingprovided with spaced upsta-nding r-ibs on the surface thereof, aplurality of terminals separated from each other and mounted in eachshoulder, each terminal having an external end accessible at the outsideof the receptacle but separated from the external ends of the otherterminals by said ribs'and having its inner end terminating Within thereceptacle, conductors Within said receptacle electrically connectingsaid units with one another and with the inner ends of said terminals, afusible compound in the receptacle sealing said conductors and saidcomponents therein, certain of said external terminals being connectibleto the tWo sides of a telephone line, certain others of said externalterminals being electrically connected to said transmitter, saidreceiver and said ringer.

3. A substation apparatus unit comprising a receptacle containingelectrical units including an induction coil and a capacitor, one sideof said receptacle having an offset portion to provide a shoulder,terminals, each sealed in said shoulder to have an inner terminal endwithin the receptacle and an outer terminal end accessible from theexterior of the receptacle, conductors Velectrically connecting saidcoil and capacitor to said inner terminal ends.

4. A substation apparatus unit comprising a receptacle having a shoulderat one end thereof and having two shoulders in stepped relation at theother end thereof, a plurality of terminals mounted in each shoulder,each terminal having an external end accessible at the outside of thereceptacle and having its inner end terminating Within the receptacle,electrical units including an induction coil with its several windingsand a capacitor contained within the receptacle, conduotors within saidreceptacle electrically connecting said units with one another and withthe inner ends of said terminals, and a fusible compound in thereceptacle sealing said conductors and said units therein.

LELAND A. REED.

